NTSB sends investigators to Seattle, Arizona, Japan for 'Dreamliner' probes

The agency said it also sent personnel to Arizona to test components of the battery in question, a lithium-ion APU model.

The NTSB said its workers in Seattle are participating in the FAA's "comprehensive" 787 review. The Department of Transportation has said the FAA's probe is the one that will have be completed before the 787 is cleared to fly again. 

The NTSB said last week that the batteries on a 787 that caught fire exhibited signs of accelerated temperature increases and short circuiting.